Air nozzle for fluid fuel burners



1951 A. ECKSTEIN ET AL 2,541,347

AIR NOZZLE FOR FLUID FUEL BURNERS Filed Dec. 25, 1946 2 Sheets-Sheet 1 jflozvzeys Feb. 13, 1951 'A. ECKSTEIN ETAL AIR NOZZLE FOR FLUID FUEL- BURNERS 2 Sheets-Sheet 2 Filed Dec. 23, 1946 172 wave 'zo r19: Jfirveo Ia! 227311525622 Patented Feb. 13, 1951 AIR NOZZLE FOR FLUID FUEL BURNERS Arnold Eckstein, McHenry, and Herman Bogot,

Chicago, 111., assignol's to Ace Engineering Company, Chicago, Ill., a corporation of Illinois Application December 23, 1946, Serial No. 718,010

7 Claims.

This invention relates to nozzles for fluid fuel burners, and relates particularly to nozzles for controlling the flow of primary air for mixing with the fuel.

The type of nozzle to which the present invention is applied includes a central fuel nozzle, and a surrounding air nozzle having an outlet adjacent the outlet of the fuel nozzle. The fuel emerging from the fuel nozzle diverges, and the air nozzle is designed for directing primary air into the stream of fuel to support combustion.

Such stream of primary air must be accurately controlled to provide efficient combustion. It has been found that a spiralling stream of primary air affords the best mixing of fuel and air.

In all installations it is of course necessary to calculate the amounts of fuel and air required, and it is also necessary to predetermine the required degree of spiralling of the air stream. Whether an efiicient flame is produced can be detected instantly by an expert, and when the most efiicient flame does not result, it is necessary to change the degree of spiralling of the air after the installation is in. It is almost always necessary to make such changes after the installation is made, in spite of the most thorough and careful calculation made beforehand.

A serious objection to previous devices, and one which the present invention overcomes, is that no means existed for conveniently altering the control of the air. Vanes or bafiles were provided in the annular space between the fuel nozz e and air nozzle, and these vanes were angled to produce a circumferential stream of air. In previous devices such vanes were fixed in predetermined position, and when it became necessary to alter the vanes, a major operation resulted.

An important object therefore, of the present invention is the provision of adjustable vanes for controlling the stream of primary air.

Another important object is the provision of means for ad usting such vanes after an installation is made and completed.

A further advantage is that such vanes can be adjusted from outside the outer air nozzle. The vanes are pivoted in the air nozzle and are connected to a ring surrounding the air nozzle, and by rotation of the ring the angle of the vanes can be altered.

A still further advantage is that means is provided for locking the ring and the vanes in position after setting thereof.

With these and other objects in view, our invention consists in the construction, arrangement and combination of the various parts of our device whereby the objects contemp ated are attained, as hereinafter more fully set forth, pointed out in the claims and illustrated in the accompanying drawings, in which:

Figure 1 is a longitudinal section through the nozzle of our invention;

Figure 2 is a cross-sectional view taken on line 2-2 of Figure 1;

Figure 3 is an elevational View of the nozzle; Figure 4 is a view taken on line 4-4 of Fig- Figure 5 is a view taken on line 5-5 of Fi ure 4;

Figure 6 is a view taken on line 66 of Figure 1;

Figure 7 is a view similar to Figure 6 showing the vane thereof in a different angular position; and

Figure 8 is an exploded perspective view of one of the vanes and its pivotal supporting means.

Referring now in detail to the drawings, a combination fuel-air nozzle is indicated at [2 shown secured to the outlet element 14 of a burner 15. The fuel-air nozzle l2 includes a central fuel nozzle 96 in the form of a tube diverging toward its outlet, and secured to a fuel line it in the burner. The fuel nozzle I6 may be any of a number of conventional nozzles, and does not in itself form a part of the present invention.

Surrounding the fuel nozzle I6 is an air nozzle 29 formed of a tube 22 having exterior threads on its inner end by which it is threaded in a flanged coupling 2e and fixedly secured thereto by means of a set screw 26. The coupling 24 is directly secured to the outlet element of the burner [A by bolts or screws (not shown).

The inner surface of the outer end of the tube 22 of the air nozzle 25 is curved inwardly, toward the axis, as shown at 28 to form a constricted outlet (it which closely approaches the fuel nozzle tube it, at a point slightly inwardly of the outlet thereof. The longitudinal curvature of the portion 28 is approximately the same as the circumferential curvature, the purpose of which will appear later.

Formed on the exterior of the air nozzle tube 22, intermediate its ends, is a circumferential bead 32, and spaced forwardly of the bead 32 is a second bead 34, of greater axial extent than the bead 32, and having a reerwardly sloping rear shoulder 35. The bead 34 is provided with a plurality of circular cavities t8 spaced circumferentially therearound, and each opening out of the forward face or shoulder of the bead 3 as indicated at 49 (Figs. 6 and '7).

A plurality of vanes 22 are positioned in the annular space between the fuel nozzle !6 and air nozzle 28. Each vane t2 comprises a body portion t having a substantially straight edge disposed toward the fuel nozzle tube !6, and a curved edge opposite thereto, defining a segment of a circle. The curved edge of the vane corresponds to and is necessitated by reason of the circumferential curvature of the inner wall of the tube 22, so that said vanes may be rotated to a position in the tube approaching trans-axial relation. A projection. lE extends from the curved edge of each vane and through a circular opening 48 in the wall of the tube 22. A pluralit of openings 43 are provided concentric with the circular cavities 38 respectively.

The mounting means for the vanes 62 consists of a disc 50' having a central axial projection 52. The projections 52 are slotted centrally as indicated at 54!, and the slot extends radially through one side of the discs 56. The discs 56 are fitted in the cavities 38 with the projections 52 fitted in the openings 48. The vanes are then inserted into the tube 22, and their projections 36 are then fitted in the slots 5 in the projections 52 of the discs 58, and pins 56 are driven in holes extending diametrically through the discs, and through holes in the projections by access through the openings id, thereby pivotaily securing the vanes in the air nozzle 2G. Washers 57 are mounted on the ends of the projections 52, and seat against the inner surface of the tube 22 and against the curved edge of the vanes to insure free pivotal movement of the vanes.

Surrounding the air nozzle tube 22, adjacent its outlet end, is a ring 58 having an inwardly facing interior shoulder Bii. When the ring 5% is in tion the shoulder 59 bears against the portions of the discs .34! extending out of the openings 3G in the cavities 38. One or more set screws in the inner end of the ring 58 serve to lock the ring $3 in place, relatively to the tube 22, by hearing on the sloping shoulder of the 3 3.

A plurality of pins at project ii dly from the ring and extend into the slots in the 553, the discs being positioned wi.

slots w registering with the opening extending toward the outlet end. of the nozzle. l -ihsn the discs 55 are thus positioned, the vanes 32 are tioned longitudinally of the nozzle.

As the fuel emerges from the fuelnozzle it, it spreads into a cone-shaped stream. Primary air emerges from the outlet element id of the c and through the annular space between th fuel nozzle iii and the air nozzle The curved portion 28- and constriction 3B of he air nozzle serve todeflect the. air into the stream of fuel and mixes it therewith for supporting combustion.

The. next step in the air-fuel. mixing operation is the spiralling of the air stream. Th vanes 62 are shown in axial alignment in Fig. 1. To position the vanes at an angle, the set screws 52 are loosened, and the ring 53 is rotatably adjusted on the nozzle in one direction or the other to obtain a desired effect in admixing of air and fuel for combustion. As the ring is rotated, the pins 6 operating in the slots 5i of the discs 56 rotate said discs and thereby the vanes 32. The shoulder 69 on the ring bearing on the discs also tends to assist in rotating them. The specific construction of the operating connection between the ring 58 and the discs 5% may be of various forms, e. g., a rack and pinion arrangement might well be employed.

Figure 7 shows one vane t2 in an angled position such as might be employed in an operating installation. With the vanes in such angled positions the stream of air is given a spiralling motion around and into the fuel stream. After the vanes 52 are set in the position desired, the set screws 52 are tightened, locking the ring 58 and the vanes in position. The sloping shoulder it of the bead 3d insures that the ring 53 will be wedged into tightly locked position. By such wedging action, the shoulder 30 is brought to bear on the marginal edges of the discs 58, providing a further locking effect on the vanes.

It will be noted that the diametrical extent of the vanes i2 is such as to substantially fill the annular space between the fuel nozzle it and the air nozzle 20.

Thus, substantially all of the stream or primary air is efiectivel bafiied in the desired direction. This feature is made possible by the special shapes of the curved portion 28 of the air nozzle and the corresponding curvature of the adjacent edge of the vanes. As the vanes are turned the relative curvature of the vanes and the curved portion 28 remains the same, since the curvature of the portion 28 is the same longitudinally and circumferentially. Such curvature is therefore substantially that of a section of a sphere. A a result, the vanes, in any position, substantiallyfi-ll the annular space between the fuel nozzle. tubeand the air nozzle tube, and; their foremost tips are disposed. adjacent the constriction 30 of the air nozzle tube 22, if not the outlet edge of the fuel: tube. The correspondence. of the curvature of the vanes and the circumferential curvature of the air nozzle tube 22' is shown in Fig. 2 byth'e: dotted lineposition of one of the vanes as indicated at 66. In this representation the.- clearance between the curved edge of the vane andv inner wall of the tube 22, is exaggerated for convenience in illustration- Furthermore, the vanes, never, in practical use, are caused to be disposed transa'xially of the tube as shown at E5. The position of the vane as indicated at 58 in Figure 2, shows an operative angular position of adjustment of the van-e, similar to the position shown in Figure 7.

It will thusbe obvious that the positions of the vanes 42' can be quickly and easily varied and the. characteristic of the flame varied and controlled, after the complete installation is made, by merely adjusting the ring 53'. There is no necessity to dismantle the nozzle, nor replace it with a nozzle having different arrangement and angular disposition of vanes, as has heretofore been the practice. Thus by virtue of the present invention, it is possible to quickly and easily change the size and/or shape or characteristics of the flame to accommodate various sizes and shapes of fire boxes, and to readily compensate for varitaions in draft conditions encountered in different installations.

While we have shown a particular embodiment of our invention, it will be understood of course that we do not wish to be limited thereto since many modifications may be made, and we therefore contemplat by the claims appended hereto to cover any such modifications or substitutions of equivalents as fall within the true spirit and scope of our invention.

We claim:

1. An air nozzle for a. burner nozzle, comprising, in combination, an air outlettube, a plurality of vanes pivotally mounted in the interior of said tube. adjacent its outlet end, said vanes having pivotal portions. extending through the wall of said tube, a ring surrounding said tube adjacent the outer end thereof and rotatable. thereon, said ring having a shoulder on its inner surface facing inwardly from the outletend of said tube and having friction engagement. with the pivotal portions of said. vanes, said tube having. a shoulder on its outer surface positioned inwardly of the pivotal portions of said vanes'with respect to the outlet end of the tube, and facing inwardly of said outlet end. said ring having projections engaging the pivotal portions of said vanes, being adapted upon rotation of said ring, for swinging said vanes about their pivot mountings, and locking means on said ring having. friction engagement with the shoulder on said tube for retaining said ring on said tube.

2. An air nozzle for a burner nozzle, comprising, in combination, an air outlet tube, a plurality of vanes pivotally mounted in the interior of said tube adjacent its outlet end, said vanes having pivotal portions extending through the wall of said tube, a ring surrounding said tube adjacent the outer end thereof and rotatable thereon, said ring having a shoulder on its inner surface facing inwardly from the outlet end of said tube and having friction engagement with the pivotal portions of said vanes, said tube having a shoulder on its outer surface positioned inwardly of the pivotal portions of said vanes with respect to the outlet end of the tube, and facing inwardly of said outlet end, said ring being adapted, on rotation of the ring, for swinging said vanes about their pivotal mountings, said shoulder on said tube sloping inwardly from the outlet end of the tube, and locking means on said ring having frictional engagement with said shoulder on said tube.

3. An air nozzle for a burner nozzle, comprising, in combination, an air outlet tube, said tube having an exterior circumferential bead positioned adjacent the outlet end of the tube, said bead having a shoulder facing toward the outlet end of the tube, said bead having circular cavities facing diametrically outwardly of the tube and opening axially through said shoulder toward the outlet end of the tube, a plurality of vanes pivotally mounted in the interior of said tube adjacent its outlet end, said vanes having pivotal portions extending through the wall of the tube and into said cavities, discs fitted in said cavities and rotatable therein, said discs being secured to the pivotal portions of said vanes, said bead having an inner shoulder sloping inwardly of the outlet end of the tube, a ring surrounding said tube and rotatable thereon, said ring having an interior shoulder engaging said discs, said discs having radial slots therethrough, inwardly extending projections on said ring engageable in said slots, said ring, upon rotation thereof, adapted to swing said vanes about their pivotal mountings, and locking means in said ring engageable with said inner sloping shoulder on said tube for locking said ring in a desired position of rotative adjustment.

4. In a burner nozzle construction, a central fuel outlet tube; an outer air nozzle tube surrounding said fuel tube and forming an annular space therewith, a plurality of vanes disposed in said annular space and pivotally mounted in said air nozzle tube, said vanes being pivoted on axes disposed radially of said air nozzle tube and having portions extending through the wall thereof, discs secured to the extending portions of said vanes on the outer surface of said air nozzle tube, said discs being coaxial with said vanes, and a ring mounted on the outer surface of said air nozzle tube and rotatably adjustable thereon, said ring having friction engagement with the peripheries of said discs.

5. In a burner nozzle construction, a central fuel outlet tube; an outer air nozzle tube surrounding said fuel tube and forming an annular space therewith, a plurality of vanes disposed in said annular space and pivotally mounted in said air nozzle tube, said vanes being pivoted on axes disposed radially of said air nozzle tube and having portions extending through the wall thereof, discs secured to the extending portions of said vanes on the outer surface of said air nozzle tube, said discs being coaxial with said vanes, said discs having slots therein disposed radially with respect to the discs, a ring mounted on the outer surface of said air nozzle tube and rotatably adjustable thereon, said ring having friction engagement with the peripheries of said discs, and pins on said ring extending radially inwardly therefrom and fitted in said lots.

6. In a burner nozzle construction, a central fuel outlet tube; an outer air nozzle tube surrounding said fuel tube and forming an annular space therewith, a plurality of vanes disposed in said annular space, said vanes having fiat portions extending through the wall of said air nozzle tube, a disc individual to each vane, said discs being disposed on the outer surface of said air nozzle tube and having slots receiving said flat portions of said vanes, lock pins securing discs to said fiat portions of said vanes, said slots extending beyond one edge of said flat portions radially of said discs, a ring mounted on the outer surface of said air nozzle tube and rotatably adj ustable thereon, and pins on said ring extending radially inwardly therefrom and fitted in said slots.

7. In a burner nozzle construction, an outwardly flaring central fuel outlet tube, an outer air nozzle tube surrounding said fuel tube, and forming an annular space therewith, said air nozzle tube having a rear substantially cylindrical portion and a forward curved portion forming substantially a section of a sphere, said curved portion forming an annular constriction with said fuel tube adjacent the outlet end of said fuel tube, a plurality of vanes in said annular space, said vanes having pivotal portions extending radially through the wall of said air nozzle tube at substantially the juncture between said cylindrical portion and said curved portion, said vanes having arcuate surfaces conforming to the curved portion of said air nozzle tube, said arcuate surfaces extending beyond both sides of the pivot points of said vanes, said arcuate surfaces forming tapered portions on said vanes, said tapered portions extending into said constriction in one position of said vanes, and a ring mounted on the outer surface of said air nozzle tube and rotatably adjustable thereon, said ring havingoperating connection with said vanes and being operable on rotation of the ring to swing said vanes about their pivot points.

ARNOLD ECKSTEIN. HERMAN BOGOT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,434,406 Purnell Nov. 7, 1922 1,789,491 Mitchell Jan. 20, 1931 1,950,800 Kerr Mar. 13, 1934 1,970,667 Mitchell Aug. 21, 1934 2,037,395 I Seelig Apr. 14, 1936 2,063,174 Leonard Dec. 8, 1936 2,083,186 Anderson June 8, 1937 2,094,943 Gianola Oct. 5, 1937 2,108,621 Straitz Feb. 15, 1938 2,192,346 Henriksen Mar. 5, 1940 2,202,524 Hicks May 28, 1940 2,203,553 Thoresen June 4, 1940 2,271,587 Haynes Feb. 3, 1942 2,320,576 Dunn June 1, 1,943 2,380,463 Poole July 31, 1945 

